1. Field of the Invention
The present invention relates to power amplifiers, and in particular, to a signal processing method and power amplifier device that utilize constant-amplitude decomposed signals.
2. Introduction
Power amplifiers are used in a wide variety of applications, such as in communications systems for increasing the signal strength of wireless transmissions from a base station to a wireless handset while reducing interference. In an ideal linear power amplifier, the output power equals the input power multiplied by a constant that does not vary with the input power. In existing communications systems, the power amplifier is the final active component in a base station transmit path, and is, unfortunately, subject to non-linearities that add noise and cause distortion. In particular, conventional amplifiers become quickly and significantly non-linear at relatively low output and this often forces designers to trade-off efficiency for linearity.